Problem-Solving?

Question

There are 18 bikes in a bike rack. There are 4 more blue bikes then yellow bikes, and 2 less yellow bikes than green bikes. How many bikes of each color are on the rack?

ummm a little more simpler people i'm trying to help my 9 year-old sister and she has to show her work she's in the 3rd grade!!

Answer 1

Let B = blue bikes
Let Y = yellow bikes
Let G = green bikes

There are 18 bikes total:
B + Y + G = 18

There are 4 more blue bikes than yellow bikes:
B = Y + 4

There are 2 less yellow bikes than green bikes:
Y = G - 2

Solve this last equation for G:
G = Y + 2

Now substitute in for B and G:
B + Y + G = 18
(Y+4) + Y + (Y+2) = 18
3Y + 6 = 18
3Y = 12
Y = 4

Now the others can be solved easily:
B = Y + 4
B = 8

G = Y + 2
G = 6

Blue = 8 bikes
Yellow = 4 bikes
Green = 6 bikes

Answer 2

let b = number of blue bikes, y = number of yellow bikes, and g = number of green bikes, then:

b + y + g = 18, (1)
b = y + 4, (2)
y = g - 2, (3)

(3) & (2) ==> b = (g - 2) + 4 = g + 2,
(1) becomes (g + 2) + (g - 2) + g = 18,
3g = 18,
g = 6,
y = 6 - 2 = 4,
b = 4 + 4 = 8,
8 blue, 4 yellow, & 6 green bikes.

Answer 3

8 blue bikes 6 green bikes 4 yellow bikes

Answer 4

Let g = how many green bikes. Then g-2 is how many yellows, and g - 2 + 4 is blues

g + g-2 + g - 2 + 4 = 18

3g = 18; g = 6 and plug in to get how many yellows and blues

Answer 5

Let the number of yellow bike be x

No. of blue bikes= x + 4
No. of green bikes= x + 2
No. of yellow bikes= x

Since total no of bikes = 18
(x + 4) + (x + 2) + (x) = 18
3x + 6 = 18
3x = 18-6
= 12
x = 12/3
=4

No of blue bikes= x + 4 = 4 + 4 = 8
No of green bike= x + 2 = 4+2 = 6
No of yellow bikes= x = 4

Answer 6

8 blue bikes
6 green bikes
4 yellow bikes

Answer 7

no. of green bikes = x
no. of yellow bikes = y
no. of blue bikes = z

z = y + 4 - number of blue = yellow + 4
x = y + 2 - two less yellow than green, in other words yellow + 2 = green

y + y + 4 + y + 2 = 18
3y + 6 = 18
3y = 12
y = 4

Therefore:
yellow = 4
blue = 8
green = 6

Answer 8

8 blue bikes
6 green bikes
4 yellow bikes

Answer 9

there should be 8 blue bikes, 6 green, and 4 yellow. if it is some trick question then i dont know. if there are more colors then i have no idea.

sorry

Answer 10

8 Blue
6 Green
4 Yellow